Most conventional layout UAVs need to have removable wings for storage and transportation. If carbon-fiber spars have been adopted for the main structural elements of the wings, the most natural way to incorporate them into the fuselage (or engine nacelles) is to provide a suitable tubular opening in the fuselage into which an extension of the wing main spar slides and can be clamped. Alternatively, a continuous wing spar that spans both wings can be used,
Figure 3.6 SLS nylon wing rib with spar hole - note the extended load transfer elements that are bonded to the main foam parts of the wing and also flap hinge point.
running through a tube in the fuselage and being clamped into the wings at either end. To carry wing moments into the main structure, some kind of torque peg near the rear of the wing will also be required - since this acts in shear, it can be quite small provided the wing moments are adequately controlled along the span of the wing. We have used both a secondary spar with matching fuselage tube and a simple SLS nylon peg formed onto the innermost wing rib with acceptable results in both cases. Figure 3.7 shows the carbon spars protruding from
Figure 3.7 Two wing foam cores with end rib and spar inserted - note in this case the rib does not extend to the rear of the section, as a separate wing morphing mechanism will be fitted to the rear of the wing.
Figure 3.8 SPOTTER UAV wing under construction showing the two-part aileron plus flap, all hinged off a common rear wing spar - note also the nylon torque peg on the rib nearest the camera.
a pair of morphing wings, while Figure 3.8 shows the use of a nylon peg printed into the innermost rib.